To prevent an illegal act called “theft from a car”, it is required for cars or automotive vehicles to have a sufficient durability against a destructive act from outside the vehicles. Generally, in automotive vehicles, front and rear window glasses and door glasses are fitted in a steel-made vehicle body, and these glasses are much more fragile than steel plates. Thus, such glasses are reinforced by heat treatment and/or by thickness increase. It is necessary to quantitatively confirm whether such reinforcing measures meet various criteria (anti-crime or crime-prevention criteria), and various impact (resistance) test apparatus have so far been used for such purposes.
One example of the impact test apparatus of the aforementioned type is known from Japanese Patent Application Laid-Open Publication No. 56-43526 (JP 56-43526 A) which discloses a dent test apparatus. The disclosed dent test apparatus will be discussed below with reference to FIGS. 11A and 11B hereof.
As shown in FIG. 11A, the disclosed dent test apparatus 101 includes: a support post 103 fixedly mounted on a support table 102; an arm 104 vertically swingably mounted on a shaft 109 that is in turn provided on the support post 103; a hammer 105 fixed on a distal end surface portion of the vertically swingable arm 104; a handle 106 provided on another distal end surface portion of the arm 104; and a locking device 107 for locking the arm 104 at a swinging-movement start position.
First, a human test operator holds the handle 106 to cause the arm 104 to be locked with the locking device 107. Then, the human test operator sets an object of test 108 on the support table 102 and then operates the locking device 107 to disengage the arm 104 from the locking device 107. As shown in FIG. 11B, the thus-disengaged arm 104 pivots about the shaft 109 downwardly or counterclockwise, so that the hammer 105 hits the object of test 108.
In the aforementioned manner, the conventionally-known dent test apparatus can readily and accurately reproduce an intensity and direction of energy applied at the time of an impact.
In a case where the object of test is a glass of an automotive vehicle, it is recommendable that the dent test be carried out by the glass being successively hit a plurality of times, e.g. five times. Thus, in this case, the human test operator has to repeat lifting and dropping the arm 104 a plurality of times, which would undesirably increase a load on the test operator and necessary test time and thus lead to a lowered test efficiency.